Universal Transmitter, Length 29/32 in, Width 3 1/2 in, Height 1 45/64 in, For Use With Normally Open/Closed Contact, TABS (R) Fall Monitors, Pirs, Tempature Sensors, Status Relays, Photo-Electric Beams, Binary Output Device, Voltage 3, Includes Mounting Hardware, Color Tan, Battery Type 123A Lithium